Miksi kahvi ei maita?

Itsellä on vähentynyt suolan ja sokerinkin tarve huomattavasti joogavuosien myötä ja käsitän sen itse siten, että elimistöni on puhdistunut kaikenlaisesta kuonasta säännöllisen liikunnan ansiosta ja tasapaino on vihdoinkin löytynyt. Ennen olin mitä melkoinen sokerihiiri ja suolaakin piti vetää sitten "vastapainoksi" yhtä paljon.
Ehkä kofeiinilla on hiukan sama elinkaari joidenkin joogaajien elämässä. Se on vahvempi piriste kuin teen teiini.
No, itse en juo teetä enkä kahvia, joten jätänpä niiden spekuloinnin tähän.

"Caffeine is an addictive drug. Among its many actions, it operates using the same mechanisms that amphetamines, cocaine, and heroin use to stimulate the brain. On a spectrum, caffeine's effects are more mild than amphetamines, cocaine and heroin, but it is manipulating the same channels, and that is one of the things that gives caffeine its addictive qualities."

"As adenosine is created in the brain, it binds to adenosine receptors. The binding of adenosine causes drowsiness by slowing down nerve cell activity. In the brain, adenosine binding also causes blood vessels to dilate (presumably to let more oxygen in during sleep).


To a nerve cell, caffeine looks like adenosine. Caffeine therefore binds to the adenosine receptor. However, it doesn't slow down the cell's activity like adenosine would. So the cell cannot "see" adenosine anymore because caffeine is taking up all the receptors adenosine binds to. So instead of slowing down because of the adenosine level, the cells speed up. You can see that caffeine also causes the brain's blood vessels to constrict, because it blocks adenosine's ability to open them up. This effect is why some headache medicines like Anacin contain caffeine -- if you have a vascular headache, the caffeine will close down the blood vessels and relieve it.

So now you have increased neuron firing in the brain. The pituitary gland sees all of the activity and thinks some sort of emergency must be occurring, so it releases hormones that tell the adrenal glands to produce adrenaline (epinephrine)."

"Caffeine also increases dopamine levels in the same way that amphetamines do (heroine and cocaine also manipulate dopamine levels by slowing down the rate of dopamine re-uptake). Dopamine is a neurotransmitter that, in certain parts of the brain, activates the pleasure center. Obviously, caffeine's effect is much lower than heroin's, but it is the same mechanism. It is suspected that the dopamine connection contributes to caffeine addiction."

"The problem with caffeine is the longer-term effects, which tend to spiral. For example, once the adrenaline wears off, you face fatigue and depression. So what are you going to do? You take more caffeine to get the adrenaline going again. As you might imagine, having your body in a state of emergency all day long isn't very healthy, and it also makes you jumpy and irritable.

The most important long-term problem is the effect that caffeine has on sleep. Adenosine reception is important to sleep, and especially to deep sleep. The half-life of caffeine in your body is about 6 hours. That means that if you consume a big cup of coffee with 200 mg of caffeine in it at 3:00 PM, by 9:00 PM about 100 mg of that caffeine is still in your system. You may be able to fall asleep, but your body probably will miss out on the benefits of deep sleep. That deficit adds up fast. The next day you feel worse, so you need caffeine as soon as you get out of bed. The cycle continues day after day."

"Once you get in the cycle, you have to keep taking the drug. Even worse, if you try to stop taking caffeine, you get very tired and depressed and you get a terrible, splitting headache as blood vessels in the brain dilate. These negative effects force you to run back to caffeine even if you want to stop."


www.howstuffworks.com


Kaikesta huolimatta, kahvi on kyllä aika herkku. Tässä yksi useamman vuoden joogaillut joka ei aio jättää kahvia.